The invention relates to a method for the amplification of ribonucleic acid (RNA), in which all the ingredients needed for the various reactions are introduced into the starting solution, all the steps being performed in the same container and without subsequent addition of any ingredient. It is thus possible to work in a closed container throughout the duration of the operations, and hence to reduce the risks of accidental contamination and the risk of manipulation error.
The ability now exists to amplify a DNA sequence without it being necessary to clone it in a host cell. The best known technique in this field is the so-called polymerase chain amplification technique, often designated by the acronym PCR, described, for example, in U.S. Pat. Nos. 4,683,195 and 4,683,202.
The PCR amplification method may be combined with a prior stop of reverse transcription in order to amplify an RNA sequence in the form of DNA.
The polymerase chain amplification reaction coupled to reverse transcription (often designated in abbreviated form by the acronym RT-PCR) is now widely used to monitor gene expression at messenger RNA (mRNA) level, as well as for the direct cloning of coding sequences.